A drilling rig includes a mast to support a crown block, travelling block (and, e.g., a top drive) and, ultimately, a drill string. In some drilling rigs, during rig-up, the mast may be raised from a substantially horizontal position to a substantially vertical position. In these drilling rigs, the mast is raised using two three-stage (also called three-phase) telescopic cylinders. A first end of each cylinder is coupled to a fixed location on the mast, and a second end of each cylinder is coupled to a fixed location on the lifting base. To raise the mast, the cylinders telescopically extend in sequence proceeding from the largest portion of each cylinder to the smallest portion of each cylinder.
The cylinders are long (e.g., up to 60 feet or about 20 m) and generate large forces (e.g., 800+ klbs or about 363 Mg). Due to their relatively small diameter in relation to their length and the forces to which they are subjected, the bending forces applied to the cylinders may lead to leakages, cylinder failure, and ultimately mast collapse.